These questions all depend on the type of position you are applying for. If the position is a product support position, then time spent on the phone is going to be large. Let's say your previous work involved working alone a lot, and the position you are applying for requires a lot of teamwork. Even though you worked by yourself a lot, you should emphasize the work you did in teams. If this is the situation, then I would say I did a combination of both.

This is not an extravagant answer, but it definitely shows that this person is capable of working in groups and working alone. Most office work requires a combination of working in groups and alone, but if your situation is different, then answer according to what the interviewer wants to hear.